The present invention relates generally to communication devices, and more particularly to a method for establishing a communication link between a communication device and authorization equipment.
A cordless telephone system typically includes a portable cordless handset and a cordless base station connected to a telephone company phone system by telephone landlines. The cordless base station has an assigned landline telephone number that allows the user to place and receive calls using the cordless portable handset within a limited range of the cordless base station, such as in a home. However, due to their limited range, the cordless portable handset provides the user with relatively local radiotelephone communication.
Radiotelephone communication outside the range of the cordless telephone system may also be provided to the user via a cellular telephone system. A cellular telephone system typically includes cellular subscriber units (mobile or portable) and cellular base stations connected to the landline telephone system via one or more cellular switching networks. Each cellular subscriber unit has an assigned cellular telephone number that allows the user to place and receive calls within a widespread range of the cellular base stations, such as throughout a metropolitan area. However, the cost of using the cellular telephone service is much greater than the cordless telephone service.
A cordless communication system incorporating a portable cellular cordless (PCC) radiotelephone is shown. The PCC has the ability to communicate with a conventional cellular radiotelephone system, which has a plurality of cellular base stations, a microcellular base station, or a cordless base station, which provides private telephone line interconnection to the telephone network for the user of the PCC. The cordless communication system uses an authorization and call routing equipment to provide call routing information to a telephone switching system. Thus, the switching system automatically routes phone calls between the cellular, microcellular and cordless systems. The authorization and call routing equipment also authorizes the cordless base station to utilize channels. However, a problem exists for both the operator of the telephone network and the user of the PCC. In particular, the operator of the telephone network must ensure that a user of the PCC does not fraudulently access service in a system in which the user is not authorized to access. Similarly, the user of the PCC must ensure that the cellular system which is being accessed is not a fraudulent system (i.e. a system established by a fraudulent operator who is illegally utilizing spectrum).
Accordingly, there is a need for a method to effectively establish a communication link between a cordless base station and authorization and call routing equipment only when both the cordless base station and the authorization and call routing equipment have been authenticated to ensure that the PCC is allowed to operate on the communication system and the authorization and call routing equipment is allowed to allocate spectrum of the communication system.